Timer escapement



y 1967 R. E. MCVICKER 3,319,477

TIMER ESCAPEMENT Filed Sept. 23, 1965 INVENTOR RICHARD E. M -VICKER ATTORNEY United States Patent F of Delaware Filed Sept. 23, 1965, Ser. No. 489,720 Claims. (Cl. 74-112) The present invention relates to means and method for translating a constant rotary motion input to a step-bystep rotary motion output. More particularly, the means and method of the present invention relate to escapements imparting timed intermittent or step-by-step rotary motion output from a substantially constant rotary motion in ut.

Although the present invention is adaptable to a multiplicity of uses, a particularly useful application of the means and method is found in sequential timers of the type employed to regulate cycle programs of electrical appliances such as washing machines, dishwashers, dryers, and the like. Generally, the sequential timers utilized to control the sequence of operations of the electrical appliance are of the type having a plurality of cams fixedly attached to a rotatably driven shaft. The cams include coded indicia peripheral contours, generally rise and fall contours, on which one or more follower switches ride. The state of actuation of any particular follower switch is determined by the contours of the cam cooperatively associated with the follower switch. Each follower switch effectively controls the state of actuation of an electrical circuit associated therewith. Such electrical circuits control the programmed cycling of the electrical appliance. In the washing machine, the cams would control the washing, the rinsing, the drying, and the like portions of the programmed cycle.

In a device such as a sequential timer, it is desirable that the escape-ment translate the constant rotary motion of a drive motor to a positive intermittent rotary motion which is transferred to the cam means.

Several escapements presently available impart an intermittent or step-by-step snap rotary motion output from a substantially constant rotary motion input and are used in conjunction with a switch means to form a sequential timer. These several escapements utilize means for storage of energy during a storage cycle and for subsequent release of the stored energy during a release cycle. Generally, the means utilized to store the energize is a straight line spring that is either compressed or expanded thereby storing energy. When the straight line spring is released from its compressed or expanded condition, the energy so stored provides a driving torque for a ratchet wheel and a cam carrying shaft coupled to the ratchet wheel.

The use of the intermittent driving means provides the facility of making and breaking the switch contacts of the follower switch at sufiicient velocity so as to prevent the contacts from being damaged by arcing between cooperating follower switch contacts. The intermittent release of energy stored over a relatively long period of time during a relatively short release period is transferred to a ratchet wheel that is fixedly connected to a cam carrying shaft so as to intermittently drive the cam carrying shaft.

The present invention provides an intermittent driving means whereby the straight line spring and complicated cooperatively associated means are replaced by a simple, efficient, inexpensive, accurate, and effective coil spring, a partially toothed gear, and a partially toothed pinion 3,319,477 Patented May 16, 1967 coupled together in such a manner so as to provide an intermittent driving force which actuates a cam means that in turn controls the sequential operation of a plurality of follower switches.

Therefore, it is an object of the present invention to provide a novel rotary motion translating means utilized to translate a relatively slow, continuous rotary motion to a rapid and intermittent rotary motion.

Another object of the present invention is to provide an intermittent drive means possessing improved operating characteristics.

Still another object of the present invention is to provide an escapement means for actuating a plurality of multi-contact electrical switches, the escapement being inexpensive and accurate in construction and more positive in action than several of the prior art escapements.

A further object of the present invention is to provide an escapement in which each impulse or actuation has a precise amount of travel without overtravel.

Yet another object of the present invention is to provide an escapement means having constant torque advancement characteristics that is also simple to fabricate and assemble.

Still another object of the present invention is to provide a simple, efficient, and practical escapement means for timing devices.

Another object of the present invention is to provide an escapement means having optimum reliability characteristics afforded by a construction having a minimum number of parts.

A further object of the present invention is to provide an escapement means which can be readily fabricated and formed at low cost.

The present invention, in another of its aspects, relates to the novel features of the instrumentalities of the in vention described herein for teaching the principal object of the invention and to the novel principles employed in the instrumentalities whether or not these features and principles may be used in the said object and/or in the said field.

With the aforementioned objects enumerated, other objects will be apparent to those persons possessing ordinary skill in the art. Other objects will appear in the following description, appended claims, and appended drawings. The invention resides in the novel construc tion, combination, arrangement, and cooperation of elements as hereinafter described and more particularly as defined in the appended claims.

The appended drawings illustrate an embodiment of the present invention constructed to function in the most advantageous modes devised for the practical application of the basic principals involved in the hereinafter described invention.

In the drawings:

FIGURE 1 is an exploded perspective view of the escapement of the present invention illustrating the various components of the escapement.

FIGURE 2 is a top view of the escapement of the present invention showing a partial pinion of the escapement immediately prior to the engagement of the partial ly toothed pinion with a partially toothed spring biased gear of the escapement.

FIGURE 3 is a top view of the escapement of the present invention illustrating the partially toothed pinion immediately prior to the release of the spring biased partially toothed gear by the partially toothed pinion of the escapement.

FIGURE 4 is a cross sectional view of several com- Jonents of the escapement of the present invention showng the relative position of these several components with 'espect to each other.

Generally speaking, the present invention relates to a means and method for translating a constant rotary motion Lnput to a step-by-step rotary motion output. A partially toothed means is coupled to and driven by a drive means that has a substantially constant rotary motion output. A gear means is coupled to and driven by the partially toothed means. A means connected to the gear means is utilized for storing energy as the gear means is displaced by the partially toothed means. A one-way clutch means is carried by the gear means. A means having a sawtoothed periphery is cooperatively associated with the one-way clutch means such that the clutch means is free wheeling of the saw-tooth means as the gear means is displaced by the partially toothed means. When the partially toothed means disengages the gear means, the means that stored energy releases the stored energy thereby displacing the gear to its initial position. The clutch means of the gear engages with the saw-toothed means so as to displace the saw-toothed means a predetermined arcuate increment.

The escapement means of the present invention may be used as an important component of a sequential timer. The sequential timer may be utilized for actuating a plurality of electrical circuits. The timing device would include a drive means having a constant rotary motion output and an escapement means coupled to the output of the drive means. The escapement means translates the constant rotary motion of the drive means to an intermittent rotary motion output. A cam carrying shaft is coupled to the intermittent rotary motion output of the escapement means and is driven thereby. A timing cam means that includes a plurality of peripheral rise and fall contours is carried by the shaft and is rotatable therewith. A plurality of switch means are actuated by the displacement of the cam to thereby open and close electrical circuits coupled to the switch means.

More particularly, the present invention is directed to an escapement means having a predetermined arcuate displacement output. The escapement uses a partially toothed pinion coupled to and driven by a drive means. A partially toothed gear is coupled to and driven by the partially toothed pinion. A spring bias means is connected to the partially toothed gear. The spring bias means is utilized for storing energy as the partially toothed gear is displaced by the partially toothed pinion. A pawl means is carried by the partially toothed gear. A ratchet wheel has its saw-toothed periphery cooperatively associated with the pawl so that the pawl slidably interfits with the saw-toothed periphery of the ratchet wheel as the partially toothed gear is displaced by the partially toothed pinion. The partially toothed pinion disengages the partially toothed gear thereby causing the spring bias means to release its stored energy. The release of the stored energy causes the partially toothed gear to be displaced to its initial position. During the release of the stored energy, the pawl means engages with the ratchet wheel and arcuately displaces the ratchet wheel a predetermined arcuate increment.

Referring now to FIGURE 1 of the drawings, the escapement means of the present invention is illustrated in an exploded view. A mounting means 11 such as a fiat mounting plate serves as the main mounting plate' for a drive means such as drive motor 12. The drive motor is fixedly coupled to the mounting plate by a plurality of suitable securing means such as bolts, rivets, or the like. The mounting means and the associated bolts prevent deleterious horizontal and vertical displacement of the motor due to vibration, abusive handling or the like. The escapement means is also mounted on the main mounting plate so as to be in close proximity to the drive motor.

Typically, the drive motor is mechanically coupled to a pinion 13. The pinion is driven in a predetermined direction, such as the clockwise direction, with a substantially constant rotary motion. The main mounting plate predeterminately locates the pinion 13 with respect to a gear train 14. As shown in FIGURE 1, the gear train includes two speed reduction gears. A first speed reduction gear 15, journalled to the main mounting plate by any suitable means such as a pin, hub or the like, meshes with and is rotatably driven in the counterclockwise direction by the pinion 13 with a substantially constant rotary motion. The first speed reduction gear meshes with and rotatably drives a second speed reduction gear 16 in the clockwise direction with a substantially constant rotary motion. The second speed reduction gear is journalled to the mounting plate by any suitable means such as a hub 17 or a pin or the like.

A partially toothed pinion 18 is also journalled to the main mounting plate by hub 17. As is illustrated in FIG- URE 1, the partially toothed pinion overlays and is axially aligned with the second speed reduction gear. The partially toothed pinion is fixedly connected to the second speed reduction gear by any suitable means such as by pressure fitting, welding, soldering or the like. It will be noted that the partially toothed pinion is rotated in the clockwise direction with substantially the same speed as is the second speed reduction gear.

The partially toothed pinion 18 is illustrated as a six tooth pinion but including only four teeth 19 equally spaced each from the other about 240 degrees of the periphery of the pinion. The four teeth are shown for illustrative purposes only since the number of teeth carried by the partially toothed pinion determine the amount of energy stored in the escapement immediately prior to the release of the stored energy. With a pinion including less teeth, the energy stored by the escapement is reduced.

The partially toothed pinion meshes with and rotatably drives a partially toothed gear 20 in the counterclockwise direction. The partially toothed gear has an arcuate extent, as shown in FIGURES 2 and 3, of about 60 degrees. The arcuate extent of the partially toothed gear is for illustrative purposes only. The partially toothed gear includes an aperture 21 at one end thereof that is utilized as a means to retain a hooked end of a helical spring 22. The other hooked end of the helical spring is coupled to a post 23 stamped from the main mounting plate. It is seen that the helical spring is maintained between the aperture 21 of the partially toothed gear and the post 23 of the mounting plate such that counterclockwise displacement of the partially toothed gear displaces the coils of the helical spring such that the coils thereby store energy.

In addition, the partially toothed gear has an arcuate slot 33 near its periphery and adjacent thereto and the gear carries a one-way clutch such as pawl 24 that is spring biased toward a ratchet wheel 25 by having one end of a spring means 34 contained in the slot 33 and the other end of the spring means 34 overlying the pawl. The slot 33 also serves another purpose besides that of a seat for the spring means 34, the other purpose being to allow the teeth of the gear in proximity to the slot to be displaced a slight amount if the meshing teeth of the partial pinion are not exactly aligned thereby preventing crowning of the meshing teeth. The ratchet wheel is rotatably journalled to the mounting plate by any suitable means such as support means 26. As the partially toothed gear is driven in the counterclockwise direction by the partially toothed pinion, the pawl carried by the partially toothed gear is displaced in the counterclockwise direction. The pawl ramps up the incline of the cooperatively associated ratchet tooth until it reaches the apex of that tooth at which time the pawl descends rapidly into the valley of the adjacent ratchet tooth. The portion of the ratchet tooth adjacent the pawl is so shaped that displacement of the pawl in the clockwise direction causes the pawl to displace the ratchet wheel in the clockwise direction. A nonbackup means 32 prevents counterclockwise displacement of the ratchet wheel.

A stop post 27 is stamped from the main mounting plate at a predetermined position with respect to the partially toothed gear. It will be noted that the partially toothed gear may be displaced in the clockwise direction a predetermined arcuate extent as determined by the location of the stop post 27.

The ratchet wheel includes a plurality of projection means 28 that interfit with apertures 29 of one of a plurality of cams 30. A cam carrying shaft 31 is rotatably journalled by support means 25 as shown in FIGURE 4. The cam carrying shaft includes fixedly mounted thereto a plurality of cams 30 in spaced, parallel relationship. The cam carrying shaft projects through the longitudinal axis of the individual cams in such a manner that each of the cams is fixedly coupled to and rotatable with the cam carrying shaft.

Each of the respective cams includes on the periphery thereof a cam track including coded indicia such as rise and fall contours (not shown) or the like. Each of the peripheral cam tracks is utilized to displace a contact carrying blade (not shown) of a follower switch (not shown) to one of a plurality of predetermined positions. The position of an individual follower switch is dependent on the particular portion of the cams contour on which the follower switch is riding. Generally, the follower switch cooperatively associated with the contoured periphery of a cam is located juxtaposition the periphery of the cam. As the shaft is intermittently rotated by the action of the escapement means, the cooperatively associated follower switch is displaced by the contours of the periphery of the cam.

With the hereinbefore structural disclosure in mind and by continued reference to the several figures of the drawing, the following analysis of the operation of the present invention will further serve to amplify the novelty of the present invention.

Assuming that pinion 13 is displaced in the clockwise direction, it is seen that the pinion 13 meshes with and rotatably drives the gear train with a constant rotary motion. The partially toothed pinion is fixedly coupled to the second speed reduction gear of the gear train and therefore is driven in the clockwise direction with a constant speed.

As shown in FIGURE 2, the leading tooth of the partially toothed pinion engages with the leading tooth of the partially toothed gear and drives the partially toothed gear in the counterclockwise direction. Each succeeding tooth of the partially toothed pinion meshes with the succeeding tooth of the partially toothed gear and further displaces the partially toothed gear in the counterclockwise direction. In driving the partially toothed gear in the counterclockwise direction, the coils of the helical spring are displaced each from the other thereby storing energy in the spring.

As the partially toothed gear is displaced in the counterclockwise direction by the partially toothed pinion, the pawl carried by the partially toothed gear ramps up a cooperatively associated tooth of the ratchet wheel until it reaches the apex of the tooth at which time the pawl falls into the valley of the cooperatively associated ratchet tooth of the ratchet wheel. The partially toothed gear is continuously displaced in the counterclockwise direction until the partially toothed pinion attains a position with respect to the partially toothed gear as shown in FIGURE 3.

FIGURE 3 illustrates the cooperative position of the partially toothed pinion, the partially toothed gear and the extended or stretched helical coil spring immediately prior to the actuation of the ratchet wheel of the escapement. Continued rotational displacement of the partially toothed pinion causes the teeth of the partially toothed .pinion to cease meshing with the teeth of the partially toothed gear. It will be noted that the foregoing exists because of the fact that the four teeth shown occupy 240 degrees of the periphery of the pinion while the remaining degrees of the periphery of the pinion are devoid of teeth. Therefore, the partially toothed pinion ceases to mesh with the partially toothed gear and drive it in the counterclockwise direction. The stretched helical coil spring releases its stored energy and displaces the partially toothed gear in the clockwise direction with a rapid motion. The pawl carried by the partially toothed gear engages with the cooperatively associated tooth of the ratchet wheel as shown in FIGURE 3 and displaces the ratchet wheel in the clockwise direction with a rapid motion. The displacement of the partially toothed gear and the ratchet wheel in the clockwise direction is continuous until such time as the partially toothed gear engages with the stop post 27. The stop post prevents further clockwise displacement of the partially toothed gear and hence further clockwise displacement of the ratchet wheel. The positive stop post eliminates deleterious overthrow problems the escapement of the present invention may develop at some subsequent time during the operation thereof.

While the invention is illustrated and described in an embodiment, it will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of this invention and as set forth in the appended claims.

Having thus described my invention, I claim:

1. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partially toothed means coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a gear means coupled to and driven by said partially toothed means; means cooperatively associated with said gear means for storing energy as said gear means is displaced by said partially toothed means; a clutch means cr-ried by said gear means; and means having a saw-toothed circumference cooperatively associated with said clutch means so that said clutch means is free-wheeling of said means having a sawtoothed circumference as said gear means is displaced by said partially toothed means, said partially toothed means disengaging said gear means causing said means to release said stored energy thereby displacing said gear to its initial position, said clutch means engaging with said means having a saw-toothed circumference thereby displacing said means having a saw-toothed circumference a predetermined arcuate increment.

2. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partially toothed pinion means coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a gear means coupled to and driven by said partially toothed pinion; means connected to said gear means for storing energy as said gear means is displaced by said partially toothed pinion; a clutch means carried by said gear means; and means having a saw-toothed circumference cooperatively associated with said clutch means so that said clutch means is free-wheeling of said means having a saw-toothed circumference as said gear means is displaced by said partially toothed pinion, said partially toothed pinion disengaging said gear means causing said means to release said stored energy thereby displacing said gear to its initial position, said clutch means engaging with said means having a saw-toothed circumference thereby displacing said means having a saw-toothed circumference a predetermined arcuate increment.

3. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partially toothed pinion means coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a gear means coupled to and driven by said partially toothed pinion; means connected to said gear means for storing energy as said gear means is displaced by said partially toothed pinion; a one-way clutch means carried by said gear means; and means having a saw-toothed circumference cooperatively associated with said one-way clutch :means so that said clutch means is free-wheeling of said Lmeans having a saw-toothed circumference as said gear :means is displaced by said partially toothed pinion, said partially toothed pinion disengaging said gear means causing said means to release said stored energy thereby displacing said gear to its initial position, said clutch means engaging with said means having a saw-toothed circumference thereby displacing said means having a sawtoothed circumference a predetermined arcuate incrennent.

4. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partial toothed pinion means coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a gear means coupled to and driven by said partially toothed pinion; spring means connected to said gear means for storing energy as said gear means is displaced by said partially toothed pinion; a one-way clutch means carried by said gear means; and means having a saw-toothed circumference cooperatively associated with said one-way clutch means so that said clutch means is free-wheeling of said means having a saw-toothed circumference as said gear means is displaced by said partially toothed pinion, said ipar-tially toothed pinion disengaging said gear means caussaid spring means to release said stored energy thereby displacing said gear to its initial position, said clutch means engaging with said means having a saw-toothed circumference thereby displacing said means having a saw-toothed circumference a predetermined arcuate increment.

5. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partially toothed pinion means coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a gear means coupled .to and driven by said partially toothed pinion; helical spring means connected to said gear means for storing energy as said gear means is displaced by said partially toothed pinion; a one-way clutch means carried by said gear means; and means having a saw-toothed circumference connected to said one-way clutch means so that said clutch means is free-wheeling of said means having a saw-toothed circumference as said gear means is displaced by said partially toothed pinion, said partially toothed pinion disengaging said gear means causing said helical spring means to release said stored energy thereby displacing said gear to its initial position, said clutch means engaging with said means having a saw-toothed circumference means thereby displacing said means having a saw-toothed circumference a predetermined arcuate increment.

6. An escapement means for providing an intermittent :rotary motion output of predetermined arcuate increments comprising: a partially toothed means coupled to and 'driven by a drive means, said drive means providing a substantially constant rotary motion; a partially toothed qgear coupled to and driven by said partially toothed :means; a spring bias means cooperatively associated with said partially toothed gear, said spring bias means storing energy as said partially toothed gear is displaced by said partially toothed means; a pawl means cooperatively associated with said partially toothed gear; and a ratchet wheel having a saw-toothed periphery cooperatively associated with said pawl means so that said pawl means slidably interfits with said saw-toothed periphery of said ratchet wheel as said partially toothed gear is displaced by said partially toothed means, said partially toothed means disengaging said partially toothed gear causing said spring bias means to release stored energy thereby displacing said partially toothed gear to its initial position,

8 said pawl means engaging said ratchet wheel thereby displacing said ratchet wheel said predetermined arcuate increment.

'7. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partially toothed pinion coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a partially toothed gear coupled to and driven by said partially toothed pinion; a spring bias means cooperatively associated with said partially toothed gear, said spring bias means storing energy as said partially toothed gear is displaced by said partially toothed pinion; a pawl means cooperatively associated with said partially toothed gear; and a ratchet wheel having a saw-toothed periphery cooperatively associated with said pawl means so that said pawl means slidably interfits with said saw-toothed periphery of said ratchet wheel as said partially toothed gear is displaced by said partially toothed pinion, said partially toothed pinion disengaging said partially toothed gear causing said spring bias means to release stored energy thereby displacing said partially toothed gear to its initial position, said pawl means engaging said ratchet wheel thereby displacing said ratchet wheel said predetermined arcuate increment.

8. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partially toothed pinion coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a partially toothed gear coupled to and driven by said partially toothed pinion; a spring bias means connected to said partially toothed gear, said spring bias means storing energy as said partially toothed gear is displaced by said partially toothed pinion; a pawl means carried by said partially toothed gear, and a ratchet wheel having a saw-toothed periphery inter fitting with said pawl means so that said pawl means slidably interfits with said saw-toothed periphery of said ratchet wheel as said partially toothed gear is displaced by said partially toothed pinion, said partially toothed pinion disengaging said partially toothed gear causing said spring bias means to release stored energy there'by displacing said partially toothed gear to its initial position, said pawl means engaging said ratchet wheel thereby displacing said ratchet wheel said predetermined arcuate increment.

9. An escapement means for providing an intermittent rotary motion output of predetermined arcuate increments comprising: a partially toothed pinion coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a partially toothed gear coupled to and driven by said partially toothed pinion; a helical spring bias means connected to said partially toothed gear, said spring bias means storing energy as said partially toothed gear is displaced by said partially toothed pinion; a pawl means carried by said partially toothed gear; and a ratchet wheel having a saw-toothed periphery interfitting with said pawl means so that said pawl means slidably interfits with said saw-toothed periphery of said ratchet wheel as said partially toothed gear is displaced by said partially toothed pinion, said partially toothed pinion disengaging said partially toothed gear causing said spring bias means to release stored energy thereby displacing said partially toothed gear to its initial position, said pawl means engaging said ratchet wheel thereby displacing said ratchet wheel said predetermined arcuate increment.

It). An escapement means for providing an intermittent rotary moton output of predetermined arcuate increments comprising: a partially toothed pinion coupled to and driven by a drive means, said drive means providing a substantially constant rotary motion; a partially toothed gear coupled to and driven by said partially toothed pinion, said partially toothed gear including a slot near said periphery and adjacent thereto; a spring bias means connected to said partially toothed gear, said spring bias means storing energy as said partially toothed gear is displaced by said partially toothed pinion; a pawl means carried by said partially toothed gear; a bias means carried by said slot of said partial gear for biasing said pawl in a predetermined direction; and a ratchet Wheel having a saw-toothed periphery interfitting With said pawl means so that said pawl means slidably interfits with said sawtoothed periphery of said ratchet wheel as said partially toothed gear is displaced by said partially toothed pinion, said partially toothed pinion disengaging said partially toothed gear causing said spring bias means to release stored energy thereby displacing said partially toothed gear to its initial position, said pawl means engaging said ratchet Wheel thereby displacing said ratchet wheel said predetermined arcuate increment.

References Cited by the Examiner UNITED STATES PATENTS Poole 741 11 Poole 7443. Finehout et al 7412. Smith et a1. 741.: Harris 74-121 Simmons 74-425 Linn 74-12f FRED C. MATTERN, JR., Primary Examiner. C. J. HUSAR, Assistant Examiner. 

1. AN ESCAPEMENT MEANS FOR PROVIDING AN INTERMITTENT ROTARY MOTION OUTPUT OF PREDETERMINED ARCUATE INCREMENTS COMPRISING: A PARTIALLY TOOTHED MEANS COUPLED TO AND DRIVEN BY A DRIVE MEANS, SAID DRIVE MEANS PROVIDING A SUBSTANTIALLY CONSTANT ROTARY MOTION; A GEAR MEANS COUPLED TO AND DRIVEN BY SAID PARTIALLY TOOTHED MEANS; MEANS COOPERATIVELY ASSOCIATED WITH SAID GEAR MEANS FOR STORING ENERGY AS SAID GEAR MEANS IS DISPLACED BY SAID PARTIALLY TOOTHED MEANS; A CLUTCH MEANS CARRIED BY SAID GEAR MEANS; AND MEANS HAVING A SAW-TOOTHED CIRCUMFERENCE COOPERATIVELY ASSOCIATED WITH SAID CLUTCH MEANS SO THAT SAID CLUTCH 